Before the 1850s, most abolitionists were averse to the use of violence. Opponents of slavery hoped to use moral persuasion and other peaceful means to end slavery. But during the 1850s, the Fugitive Slave Law of 1850, the caning of Charles Sumner in the U.S. Senate chamber, violence in Kansas between pro-slavery "border ruffians" and free-soilers, and the Supreme Court's Dred Scott decision shook abolitionists' faith in nonviolence.

By the mid-1850s, a growing number of abolitionists, including John Brown, had concluded that it was just as legitimate to use violence to secure the freedom of slaves as it had been to establish the independence of the American colonies.